The International Energy Agency projects that by 2050, more than half of all oil and gas will be used to make plastics and petrochemicals. This has enormous climate impacts.
Dr. Shanna Swan, a leading reproductive epidemiologist at Mount Sinai and adjunct scientist with Environmental Health Sciences, discusses a new analysis that found that sperm count globally dropped by more than half between 1973 and 2018, and that the decline is accelerating.
Dr. Swan, a coauthor of the new analysis published in the Human Reproduction Updatejournal, outlines the implications of this infertility crisis and some of the environmental causes. Swan authored the book Count Down: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperiling the Future of the Human Race.
Watch the video above for Dr. Swan's thoughts on the latest findings, and read about the report here.
For years, scientists across the world have gathered evidence showing declines in sperm quality. Now, new research compiling the results of those studies has found that sperm count has dropped dramatically around the world, and the rate of decline is accelerating.
In a new analysis, researchers at Mount Sinai Medical Center, the University of Copenhagen, and the Hebrew University of Jerusalem, among others, found that sperm count globally dropped by more than half between 1973 and 2018, and that the decline is accelerating: Since 1972, sperm count has dropped by about 1% each year. Since 2000, the annual decrease has been, on average, more than 2.6%.
The findings raise concerns that an increasing number of people will need assistance to reproduce, as well as concerns about the overall health of human society, since low sperm count is linked to higher rates of some diseases. And while scientists are still trying to tease out the reasons for the drop, chemical exposures, especially to pesticides, are a likely factor — and climate change may even play a role. Researchers are calling for urgent action to bolster more research into sperm count, determine the causes of the decline, and prevent further deterioration of male reproductive health.
“We have clear evidence that there is a crisis in male reproduction,” Hagai Levine, lead author on the study and an epidemiologist at the Hebrew University of Jerusalem, told EHN.
The study builds on the team’s previous research, which showed a decline in sperm count in North America, Europe, Australia, and parts of Asia of 28.5% between 1973 and 2011. Adding data from 38 studies to the new analysis has made the case for sperm decline stronger, Shanna Swan, an author on the paper and a leading reproductive epidemiologist at Mount Sinai, told EHN. “It’s really alarming,” said Swan, who is also an adjunct scientist with Environmental Health Sciences, which publishes EHN.org.
The research found that the average global sperm count in 2018 was 49 million per milliliter of semen. When a man’s sperm count drops below about 45 million per milliliter, his ability to cause a pregnancy starts dropping dramatically, said Swan. She said the results could mean that in the coming decades, large swaths of the global population of men could be subfertile or infertile, or could require assisted reproduction techniques, like in vitro fertilization (IVF), hormone treatment, or a technique called intracytoplasmic sperm injection (ICSI), in which sperm are directly injected into an egg.
In addition to the drop in average sperm count, Levine said it was surprising that the rate of decline was accelerating, rather than slowing down. “Is there a tipping point, that once you cross, you get an even worse situation?” he said. “That’s something to really pay attention to.”
Overall, said Levine, the results indicate that “something is very wrong with our global modern environment.”
Sperm count is not only a reproductive concern, but an indicator for other health problems in men, and is used as a predictor for male longevity. Men with poor sperm count tend to have higher rates of cardiovascular disease, certain cancers and even death, Michael Eisenberg, a professor of urology at Stanford University who was not involved in the research, told EHN. “This decline in sperm count could also suggest other health concerns,” he said.
A 2016 study authored by Eisenberg found that diabetes and other diseases were associated with lower reproductive health. However, said Eisenberg, the reason why overall health is linked to sperm quality is still unknown.
Eisenberg said the new study on sperm count decline is a “powerful addition” to previous evidence that sperm count across the globe has declined.
Though the reasons for the drop were not discussed in the paper, scientists have known for decades that certain environmental factors, like exposures to pesticides (such as atrazine, alachlor, and diazinon) and other endocrine-disrupting chemicals, like phthalates, and polychlorinated biphenyls (PCBs), can have impacts on reproductive health. Nearly 20 years ago, for example, Swan and other researchers published an analysis of research into links between pesticide exposure and sperm quality, and found that 79% of studies indicated a decrease in sperm quality among those exposed to the chemicals. Diet, activity level, and stress may also play a role.
Swan and Levine said exposures to chemicals in the environment and other factors likely all play a substantial role in the sperm count trend. And, the risk factors are related; for example, obesity is a risk factor for lower quality sperm, but certain endocrine-disrupting chemicals — which interfere with how hormones work — are thought to contribute to obesity, as well. Diet is hard to decouple from chemical exposures, too, since pesticide residues linger on much of the food we eat.
Additionally, both Swan and Levine said climate change could be a factor, both due to climate-related stress and actual fluctuations in temperature, since heat waves are linked to decreases in sperm quality.
Prenatal exposure may be a contributor, too. Chemical exposures during the male “programming window,” when reproductive traits are formed in utero, have an outsized effect on sperm quality later in life, said Swan. For example, she said, when a man smokes — a known endocrine-disrupting activity — he lowers his sperm count by about 20%. When a male is born to a woman who smokes, his sperm count is reduced by about 50%. Those effects may last for generations before subsequent children and grandchildren return to normal sperm counts.
Levine is optimistic that scientists and policymakers can reverse the trend if they can determine the causes. Swan pointed to the sharp drop in cigarette smoking in the past 50 years as evidence that widespread lifestyle changes are possible, and said that any large-scale adoption of healthier habits, like better diets and more physical activity, can help improve reproductive health.
Making individual lifestyle changes like choosing organic, pesticide-free produce and staying away from certain plastics and chemical products can help lower a person’s exposure to endocrine-disrupting chemicals, too. However, doing so can be difficult, especially for disadvantaged populations with less access to fresh foods, higher environmental exposures, and fewer means to purchase safer, non-toxic household goods.
To truly tackle the problem, though, much more research is needed, said Swan. One thing she’d like to see would be better tracking of sperm count, similar to how the U.S. Centers for Disease Control and Prevention tracks obesity. Levine also said better surveillance tools will be crucial to understanding the problem more deeply.
Once humankind “defines a problem and puts our resources and mind into it, we find solutions that we could not have thought about when we started,” said Levine. “It's always theoretically reversible.”
What you need to know about sperm count decline across the globe.
This study shows, for the first time, that sperm counts are declining everywhere, not only in North America, Europe, Australia and New Zealand, which was shown previously, but also in South America, Asia and Africa. This new analysis found that sperm count globally dropped by more than 50% between 1973 and 2018, and that the decline is accelerating: Since 1972, sperm count has dropped by about 1% each year. Since 2000, the annual decrease has been, on average, more than 2.6%.
This accelerated decrease in global sperm counts means more people will need to use assisted reproduction to get pregnant. These findings imply more than decreased fertility; lower sperm counts are linked to more disease later in life (cardiovascular disease, diabetes and reproductive cancers) and a shorter life expectancy.
The decline is too rapid to be due to genetic causes alone. Some risk factors for lower sperm counts have to do with lifestyle; smoking, obesity, stress and binge drinking. In addition, environmental chemicals — particularly those that can alter the body’s hormones called endocrine disrupting chemicals (pesticides, phthalates, BPA, PFAS chemicals and others) — have been shown to reduce sperm counts and quality and are likely contributing to this decline.
While scientists continue to tease out the causes, men should avoid smoking, a sedentary lifestyle, excessive weight gain, drug and alcohol abuse, and potentially toxic chemicals. This means buying organic food when possible or washing fruits and vegetables that may have pesticide residues. Another good idea is avoiding plastics in food contact materials and personal care and household products that contain phthalates and other endocrine-disrupting compounds.
Read more about the new study: A new analysis shows a “crisis” of male reproductive healthWatch Dr. Shanna Swan discuss the work and implications
The midterms came and went. And because we have to, you know, count all of the ballots, some things are still unresolved. However, here are some quick environmental takeaways.
There were only two major state initiatives on energy and the environment this year.
First, a $4.2 billion measure in New York state split up this way:
New York state voters approved this measure on Tuesday.
California voters rejected Proposition 30, which would have fundedinfrastructure for zero-emissions vehicles and a Wildfire Prevention Initiative by imposing additional income taxes on top-earning Californians.
Kathy Hochul (center), governor of New York.
Re-elected governors who have vowed aggressive action on climate change include:
And then there are the newcomers: Wes Moore (D-Md.) and Maura Healey (D-Mass.)
The Atlanta Journal Constitution reported that the Warnock-Walker clash (headed for a runoff scheduled for Dec. 6) had cost the two campaigns and their worldwide financial backers a quarter billion in campaigns rooted in negative advertising. But not a word about America’s climate future — not even a hopeful one — entered the media strategy of either man.
Nor did climate draw much water in Florida, where the homes of roughly 10 million residents are in communities projected to be underwater later this century. Republican Ron DeSantis, just re-elected as governor, and re-upped Republican Senator Marco Rubio both had principal residences in doomed Dade County, just down the freeway from equally doomed Mar-A-Lago.
Oklahoma Repulican Senator Jim Inhofe, a long-time climate change denier, retired.
Credit: Gage Skidmore/flickr
Few would dispute retiring Republican Oklahoma Senator Jim Inhofe his unofficial title as Capitol Hill’s Alpha Dog of climate denial. But I’m holding him to his promise of an interview on Nov. 18, 2034, his 100th birthday. We’ll check in with Inhofe to see how his climate “hoax” is working out. Inhofe turns 88 next week and has been a senator for 28 years.
Democrat Pat Leahy also retires in January when the current Senate session ends. He’s been a pro-environment stalwart on acid rain and other issues for 48 years.
His views do not necessarily represent those of Environmental Health News, The Daily Climate, or publisher Environmental Health Sciences.
PITTSBURGH—The site of a former coal-fired power plant northwest of Pittsburgh is leaking coal ash and poisoning surrounding groundwater, according to a new report.
Coal ash, the material left behind after coal is burned, contains harmful substances like arsenic, cadmium, chromium, lead, lithium, mercury and uranium, among others. Exposure is linked to health effects like cancer, damage to the thyroid, liver and kidneys, and neurodevelopmental problems in children.
Although coal consumption has declined across the U.S., the power industry continues to generate about 70 million tons of coal ash annually, and after 100 years of burning coal, U.S. power plants have generated about five billion tons of coal ash.
The new report, published by the environmental law advocacy groups Environmental Integrity Project and EarthJustice, found that 91% of U.S. coal-fired plants have ash landfills or waste ponds that are leaking toxic chemicals and heavy metals into surrounding groundwater at levels that threaten streams, rivers and drinking water aquifers. It also found that many coal plant owners manipulate data or incorrectly claim exemptions to regulations to avoid having to clean up contamination.
“Coal plants are polluting the nation’s water illegally and getting away with it,” Lisa Evans, a senior attorney at Earthjustice and coauthor of the report, said during a news briefing. “At least 91% of them are poisoning our water with hazardous toxics and doing little or nothing to address it. This is illegal.”
The report ranks the top 10 worst contaminated coal ash sites in the country. GenOn’s New Castle Generating Plant, about 46 miles northwest of Pittsburgh, ranks sixth on the list. Groundwater near the site contains arsenic levels 372 times higher than the U.S. Environmental Protection Agency’s, or EPA’s, safety threshold, and lithium levels 54 times higher.
Arsenic exposure is linked to multiple forms of cancer, neurological impairments in children and skin conditions. Lithium exposure is linked to kidney and neurological damage, decreased thyroid function and birth defects. The GenOn plant sits along the Beaver River, which feeds into the Ohio River, which, in turn, provides drinking water to more than five million people.
U.S. Fish and Wildlife Service taking core samples after North Carolina's Dan River coal ash spill in 2014.
“In addition to the Ohio River being an important source of drinking water to many Americans, people in the region also love to fish, swim and boat out in these waters,” Zach Barber, a community organizer with environmental advocacy group PennEnvironment, who was not involved with the report, told EHN. “This pollution poses real risks that are not being taken seriously by these companies or our regulators.”
The GenOn site, which has approximately 50 acres of coal ash landfill containing about three million tons of ash, is the only location in Pennsylvania to make the report’s top 10 list. It follows coal ash dumps in Texas, Nevada, North Carolina and Wyoming (two sites), and ranks worse than sites in Maryland, Mississippi, Utah and Tennessee. The most polluted site in the nation is the San Miguel Electric Plant south of San Antonio, Texas. The report, an update to a 2019 report on coal ash sites, also details groundwater contamination at 292 additional coal plants in 43 states.
“Coal ash waste is causing widespread water contamination that threatens drinking water supplies and the environment,” Lisa Evans, senior attorney at Earthjustice, said in a statement. “In every state where coal is burned, power companies are violating federal health protections.”
In 2015, in response to nearly 160 cases of water contamination and several catastrophic coal ash spills, the EPA established the first-ever regulations governing coal ash disposal collectively referred to as the Coal Ash Rule.
The rule required sites disposing of coal ash to post groundwater monitoring reports on their websites. There’s no federal database of these notices, so the authors of the report collected and analyzed the data to create their own. They concluded that many power companies are illegally manipulating data and monitoring to avoid cleanup requirements.
Companies are supposed to collect samples from clean background wells that aren’t near coal ash disposal sites to compare against wells on site. But they found that companies often chose previously contaminated sites to use as background wells, making it harder to find evidence of coal ash pollution. Many plants also leave large parts of a disposal area unmonitored, use inappropriate statistical methods to hide patterns of contamination, and falsely attribute the contamination to another source, according to the report.
“Coal plant owners are deliberately employing tricks to hide coal ash pollution,” Evans said. “People live next to these ponds. People drink the groundwater. Families use the lakes and streams next to these ponds. Leaving ash will make people sick and harm the water they depend on…but pennies over people has always been the norm where coal ash is concerned.”
Some plant owners, including the owners of GenOn’s former New Castle Plant, say the sites were already contaminated before they arrived, so they shouldn’t be responsible for cleanup, according to the report. GenOn’s New Castle Plant landfill was built on top of an 80-year-old, 120-acre ash pond, and the company is only claiming responsibility for a small part of the landfill, according to the document.
“GenOn must apply the Rule to the landfill as a whole,” the report concludes. “This approach is not only legally required, but also common sense – there is no way to restore groundwater at the site without addressing all of the coal ash known to be buried there.”
Pennsylvania Department of Environmental Protection (DEP) spokesperson Jamar Thrasher told EHN the agency supports the EPA's enforcement of the Coal Ash Rule by checking compliance with reporting requirements and deadlines for closure or upgrades. In 2020, the DEP issued a Notice of Violation for groundwater contamination and asked GenOn to address it. The company agreed, and remediation is underway, according to Thrasher, who said the cleanup plan recommends two more years of groundwater monitoring to determine whether the cleanup measures taken so far have been effective.
GenOn did not immediately respond to a request for comment. It isn’t the only company avoiding responsibility: The report found that at nearly half of the plants causing contamination, owners are not planning any cleanup, and most have denied responsibility. Of the plants that have agreed cleanup is necessary, only a handful have cleanup plans in place, and most lack clear timelines and fall short of federal standards.
The report also notes that most coal plants are located in or near environmental justice communities (communities that are primarily made up of low-income residents and/or people of color), and that 70% of coal ash ponds that are dangerously close to groundwater are located in communities that are primarily Black or brown.
Both state agencies and the EPA have authority to enforce the Coal Ash Rule. In a few states, state regulatory agencies are actively working to enforce the rule, according to Evans, while other states rely on the EPA.
The new report recommends a number of solutions, including increased federal oversight to stop coal companies from manipulating data and improperly claiming exemptions, implementing enforceable cleanup schedules, closing loopholes for sites that are no longer operational, requiring testing of drinking water near coal ash dumps and banning dangerous re-use of coal ash (such as using it as a soil substitute).
“The first place to start is enforcing the rules we already have on the books,” Barber said. “But the only way to completely protect people from the health harms of coal is to leave it in the ground and switch to cleaner, renewable sources of energy.”